:root {
  --bg: oklch(14.5% 0.018 260);
  --surface: oklch(19% 0.022 258);
  --fg: oklch(92.5% 0.014 255);
  --muted: oklch(68% 0.035 253);
  --border: oklch(29% 0.035 255);
  --accent: oklch(68% 0.085 72);
  --virgil-signal: oklch(72% 0.15 298);

  --accent-soft: color-mix(in oklch, var(--accent) 13%, transparent);
  --fg-soft: color-mix(in oklch, var(--fg) 6%, transparent);
  --surface-raised: color-mix(in oklch, var(--surface) 84%, var(--fg));

  /* Compatibility aliases for the existing Virgil demos and paper readers. */
  --bg-card: var(--surface);
  --bg-card-hover: var(--surface-raised);
  --border-glow: color-mix(in oklch, var(--accent) 38%, transparent);
  --burgundy-dark: color-mix(in oklch, var(--bg) 82%, var(--accent));
  --burgundy: color-mix(in oklch, var(--bg) 64%, var(--accent));
  --burgundy-light: color-mix(in oklch, var(--bg) 46%, var(--accent));
  --bronze-dark: color-mix(in oklch, var(--accent) 72%, var(--bg));
  --bronze: var(--accent);
  --bronze-light: color-mix(in oklch, var(--accent) 76%, var(--fg));
  --accent-cyan: var(--accent);
  --accent-red: var(--accent);
  --ink: var(--fg);
  --grid-line: color-mix(in oklch, var(--fg) 5%, transparent);

  --font-display: 'Iowan Old Style', 'Charter', Georgia, serif;
  --font-body: 'Aptos', 'Segoe UI', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Cascadia Code', ui-monospace, monospace;

  --fs-h1: clamp(3.4rem, 8vw, 7.6rem);
  --fs-h2: clamp(2.2rem, 4.7vw, 4.8rem);
  --fs-h3: clamp(1.35rem, 2vw, 1.85rem);
  --fs-lead: clamp(1.08rem, 1.6vw, 1.35rem);
  --fs-body: 1rem;
  --fs-meta: 0.75rem;

  --gap-xs: 0.5rem;
  --gap-sm: 0.75rem;
  --gap-md: 1.25rem;
  --gap-lg: 2rem;
  --gap-xl: 3.5rem;
  --gap-2xl: 6rem;
  --container: 78rem;
  --gutter: clamp(1.25rem, 4vw, 3.5rem);
  --radius: 0.2rem;
  --radius-lg: 0.35rem;
}

*, *::before, *::after { box-sizing: border-box; }

html {
  background: var(--bg);
  color-scheme: dark;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-width: 20rem;
  overflow-x: hidden;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.6;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

body[data-page='virgil'] { --accent: var(--virgil-signal); }

body::before {
  position: fixed;
  inset: 0;
  z-index: 0;
  background: var(--surface);
  clip-path: polygon(69% 0, 100% 0, 100% 100%, 57% 100%, 72% 52%);
  opacity: 0.38;
  pointer-events: none;
  content: '';
}

body[data-page='virgil']::before {
  background: color-mix(in oklch, var(--surface) 84%, var(--accent));
  clip-path: polygon(62% 0, 100% 0, 100% 86%, 79% 100%, 54% 57%);
}

body > * { position: relative; z-index: 1; }

body.nav-open { overflow: hidden; }
img, svg, canvas { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, input { font: inherit; }
button { color: inherit; }
p { text-wrap: pretty; }
h1, h2, h3, h4 { text-wrap: balance; }

:focus-visible {
  outline: 2px solid var(--fg);
  outline-offset: 4px;
}

.skip-link {
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 100;
  padding: 0.65rem 0.9rem;
  background: var(--fg);
  color: var(--bg);
  transform: translateY(-160%);
}

.skip-link:focus { transform: translateY(0); }

.container {
  width: min(100%, var(--container));
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  position: relative;
  padding-block: clamp(4.5rem, 10vw, 9rem);
}

.section + .section { border-top: 1px solid var(--border); }
.section-tight { padding-block: clamp(3.5rem, 7vw, 6rem); }
.section-surface { background: var(--surface); }
.stack { display: flex; flex-direction: column; }
.stack > * + * { margin-top: var(--gap-md); }
.row { display: flex; align-items: center; gap: var(--gap-md); }
.row-between { display: flex; align-items: center; justify-content: space-between; gap: var(--gap-md); }
.grid-2 { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--gap-xl); }
.grid-3 { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--gap-lg); }
.grid-2-1 { display: grid; grid-template-columns: 2fr 1fr; gap: var(--gap-xl); align-items: start; }
.grid-1-2 { display: grid; grid-template-columns: 1fr 2fr; gap: var(--gap-xl); align-items: start; }

.h1, h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: var(--fs-h1);
  font-weight: 400;
  line-height: 0.92;
  letter-spacing: -0.055em;
}

.h2, h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: var(--fs-h2);
  font-weight: 400;
  line-height: 0.98;
  letter-spacing: -0.04em;
}

.h3, h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: var(--fs-h3);
  font-weight: 400;
  line-height: 1.12;
  letter-spacing: -0.025em;
}

.lead {
  max-width: 48ch;
  margin: 0;
  color: var(--muted);
  font-size: var(--fs-lead);
  line-height: 1.5;
}

.eyebrow,
.meta,
.nav-link,
.btn,
.text-link,
.filter-button,
.index-label {
  font-family: var(--font-mono);
  font-size: var(--fs-meta);
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.eyebrow { margin: 0 0 var(--gap-md); color: var(--muted); }
.meta { color: var(--muted); }
.num { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }
.kicker-line { display: flex; align-items: center; gap: 0.75rem; }
.kicker-line::before { width: 2.5rem; height: 1px; background: var(--border); content: ''; }

.topnav {
  position: sticky;
  top: 0;
  z-index: 30;
  border-bottom: 1px solid var(--border);
  background: color-mix(in oklch, var(--bg) 92%, transparent);
  backdrop-filter: blur(18px);
  box-shadow: 0 1rem 3rem color-mix(in oklch, var(--bg) 72%, transparent);
}

.topnav.is-scrolled { background: color-mix(in oklch, var(--bg) 97%, transparent); }
.topnav-inner { min-height: 4.75rem; display: flex; align-items: center; justify-content: space-between; gap: var(--gap-lg); }
.brand-link { display: inline-flex; align-items: center; gap: 0.75rem; min-height: 2.75rem; }
.brand-logo { width: 2.1rem; height: 2.1rem; border-radius: 50%; }
.brand-name { font-family: var(--font-display); font-size: 1.08rem; letter-spacing: 0.04em; }
.nav-menu { display: flex; align-items: center; gap: clamp(1rem, 2.5vw, 2.5rem); }
.nav-link { position: relative; padding-block: 1rem; color: var(--muted); transition: color 160ms ease; }
.nav-link:hover, .nav-link[aria-current='page'] { color: var(--fg); }
.nav-link[aria-current='page']::after { position: absolute; right: 0; bottom: 0.7rem; left: 0; height: 1px; background: var(--fg); content: ''; }
.menu-toggle { display: none; width: 2.75rem; height: 2.75rem; place-items: center; padding: 0; border: 1px solid var(--border); background: transparent; cursor: pointer; }
.menu-toggle-lines, .menu-toggle-lines::before, .menu-toggle-lines::after { width: 1rem; height: 1px; background: var(--fg); transition: transform 180ms ease, opacity 180ms ease; }
.menu-toggle-lines { position: relative; }
.menu-toggle-lines::before, .menu-toggle-lines::after { position: absolute; left: 0; content: ''; }
.menu-toggle-lines::before { transform: translateY(-0.32rem); }
.menu-toggle-lines::after { transform: translateY(0.32rem); }
.menu-toggle[aria-expanded='true'] .menu-toggle-lines { background: transparent; }
.menu-toggle[aria-expanded='true'] .menu-toggle-lines::before { transform: rotate(45deg); }
.menu-toggle[aria-expanded='true'] .menu-toggle-lines::after { transform: rotate(-45deg); }

.btn {
  display: inline-flex;
  min-height: 2.85rem;
  align-items: center;
  justify-content: center;
  gap: 0.65rem;
  padding: 0.75rem 1.2rem;
  border: 1px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background 160ms ease, border-color 160ms ease, color 160ms ease, transform 160ms ease;
}

.btn:hover { transform: translateY(-2px); }
.btn-primary { border-color: var(--accent); background: var(--accent); color: var(--bg); }
.btn-primary:hover { background: color-mix(in oklch, var(--accent) 84%, var(--fg)); }
.btn-secondary { border-color: var(--border); background: transparent; color: var(--fg); }
.btn-secondary:hover { border-color: var(--fg); }
.btn-ghost { min-height: 2.75rem; padding-inline: 0; color: var(--fg); }
.btn-arrow::after, .text-link::after { content: '↗'; transition: transform 160ms ease; }
.btn-arrow:hover::after, .text-link:hover::after { transform: translate(0.15rem, -0.15rem); }
.hero-cta { display: flex; flex-wrap: wrap; gap: var(--gap-sm); margin-top: var(--gap-lg); }

.hero { min-height: calc(100svh - 4.75rem); display: grid; align-items: center; padding-block: clamp(4rem, 9vw, 8rem); }
.hero-split { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(19rem, 0.95fr); gap: clamp(3rem, 8vw, 8rem); align-items: center; }
.hero-copy h1 { max-width: 9ch; }
.hero-copy .lead { margin-top: var(--gap-lg); }
.hero-center { max-width: 58rem; margin-inline: auto; text-align: center; }
.hero-center .lead { margin: var(--gap-lg) auto 0; }
.hero-center .hero-cta { justify-content: center; }

.hero::after {
  position: absolute;
  top: 50%;
  right: 0.85rem;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  writing-mode: vertical-rl;
  transform: translateY(-50%);
  opacity: 0.62;
  content: '';
}

body[data-page='home'] .hero::after { content: 'Headquarters / Room 00'; }
body[data-page='departments'] .hero::after { content: 'Department directory / Room 01'; }
body[data-page='virgil'] .hero::after { content: 'Virgil / Cognitive systems'; }
body[data-page='publications'] .hero::after { content: 'Publications / Reading room'; }
body[data-page='about'] .hero::after { content: 'Company dossier / Registry'; }

.fold-frame {
  position: relative;
  min-height: clamp(24rem, 48vw, 38rem);
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--surface);
  clip-path: polygon(0 8%, 74% 0, 100% 22%, 92% 100%, 18% 92%);
  box-shadow: 2.5rem 2.5rem 0 var(--fg-soft);
}

.fold-frame::before,
.fold-frame::after {
  position: absolute;
  z-index: 2;
  pointer-events: none;
  content: '';
}

.fold-frame::before { inset: 14% 13% 18% 17%; border: 1px solid var(--border); transform: skewY(-7deg); }
.fold-frame::after { top: 0; bottom: 0; left: 52%; border-left: 1px solid var(--border); transform: rotate(14deg); }
.fold-canvas { width: 100%; height: 100%; position: absolute; inset: 0; }
.fold-caption { position: absolute; right: 8%; bottom: 9%; z-index: 3; width: 15rem; padding-top: 0.8rem; border-top: 1px solid var(--border); color: var(--muted); font-size: 0.85rem; }

.section-heading { display: grid; grid-template-columns: minmax(0, 1fr) minmax(16rem, 0.55fr); gap: var(--gap-xl); align-items: end; margin-bottom: clamp(3rem, 7vw, 6rem); }
.section-heading .lead { justify-self: end; }
.section-fold::before { position: absolute; top: 0; bottom: 0; left: calc(50% + min(30rem, 38vw)); width: 1px; background: var(--border); content: ''; transform: skewX(-8deg); pointer-events: none; }

.log-list { border-bottom: 1px solid var(--border); }
.log-row { display: grid; grid-template-columns: 9rem minmax(0, 1fr) auto; gap: var(--gap-lg); align-items: start; margin-inline: -1rem; padding: 2rem 1rem; border-top: 1px solid var(--border); transition: background 180ms ease, border-color 180ms ease; }
.log-row h3 { transition: transform 160ms ease; }
.log-row:hover { border-color: var(--fg); background: var(--fg-soft); }
.log-row:hover h3 { transform: translateX(0.35rem); }
.log-row p { max-width: 58ch; margin: 0.5rem 0 0; color: var(--muted); }
.log-row .pull { justify-self: end; }
.log-row[hidden] { display: none; }

.feature { padding-top: 1.4rem; border-top: 1px solid var(--border); }
.feature-index { display: block; margin-bottom: clamp(3rem, 7vw, 6rem); color: var(--muted); font-family: var(--font-mono); font-size: 0.72rem; }
.feature h3 { margin-bottom: 0.8rem; }
.feature p { margin: 0; color: var(--muted); }

.split-panel { display: grid; grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr); gap: clamp(3rem, 8vw, 8rem); align-items: start; }
.split-panel .lead { margin-top: var(--gap-lg); }
.principle-list { border-top: 1px solid var(--border); }
.principle-row { display: grid; grid-template-columns: 3.5rem 1fr; gap: var(--gap-md); padding-block: 1.4rem; border-bottom: 1px solid var(--border); }
.principle-row p { margin: 0.35rem 0 0; color: var(--muted); }

.card { position: relative; overflow: hidden; border: 1px solid var(--border); border-radius: var(--radius-lg); background: var(--surface); padding: clamp(1.5rem, 3vw, 2.5rem); transition: transform 220ms ease, border-color 220ms ease, box-shadow 220ms ease; }
.card::after { position: absolute; right: -2.5rem; bottom: -3.25rem; width: 8rem; height: 8rem; border: 1px solid var(--border); transform: rotate(34deg); content: ''; }
.card:hover { border-color: var(--fg); transform: translateY(-0.45rem); box-shadow: 1rem 1rem 0 var(--fg-soft); }
.card-rule { padding-top: 1.5rem; border-top: 1px solid var(--fg); }
.card h3 { margin-bottom: 0.8rem; }
.card p { margin: 0; color: var(--muted); }
.card .text-link { margin-top: var(--gap-lg); }
.text-link { display: inline-flex; align-items: center; gap: 0.55rem; color: var(--fg); }
.text-link:hover { color: var(--accent); }

.media-frame { overflow: hidden; border: 1px solid var(--border); background: var(--surface); }
.media-frame img { width: 100%; height: 100%; aspect-ratio: 16 / 10; object-fit: cover; filter: grayscale(0.78) contrast(1.05); transition: filter 220ms ease, transform 500ms ease; }
.media-frame:hover img { filter: grayscale(0.2); transform: scale(1.015); }
.media-caption { display: flex; justify-content: space-between; gap: var(--gap-md); padding: 0.85rem 1rem; border-top: 1px solid var(--border); color: var(--muted); font-family: var(--font-mono); font-size: 0.7rem; text-transform: uppercase; }

.flowmap-frame {
  position: relative;
  min-height: clamp(28rem, 52vw, 43rem);
  overflow: hidden;
  border: 1px solid color-mix(in oklch, var(--accent) 42%, var(--border));
  background: color-mix(in oklch, var(--surface) 92%, var(--accent));
  box-shadow: 2rem 2rem 0 var(--accent-soft);
}

.flowmap-frame::before {
  position: absolute;
  top: 1.1rem;
  left: 1.1rem;
  z-index: 2;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  content: 'Live state field / pointer perturbs flow';
}

.flowmap-frame::after {
  position: absolute;
  inset: 3.5rem 1.1rem 1.1rem;
  z-index: 2;
  border: 1px solid var(--border);
  pointer-events: none;
  content: '';
}

.flowmap-canvas { position: absolute; inset: 0; width: 100%; height: 100%; }
.flowmap-legend { position: absolute; right: 1.65rem; bottom: 1.55rem; left: 1.65rem; z-index: 3; display: flex; flex-wrap: wrap; justify-content: space-between; gap: 0.8rem; color: var(--muted); font-family: var(--font-mono); font-size: 0.65rem; letter-spacing: 0.08em; text-transform: uppercase; pointer-events: none; }
.flowmap-legend span { display: inline-flex; align-items: center; gap: 0.45rem; }
.flowmap-legend span::before { width: 0.35rem; height: 0.35rem; border: 1px solid var(--accent); border-radius: 50%; content: ''; }

.pipeline { counter-reset: pipeline; border-top: 1px solid var(--border); }
.pipeline-step { counter-increment: pipeline; display: grid; grid-template-columns: 4rem minmax(0, 1fr); gap: var(--gap-lg); padding-block: 1.6rem; border-bottom: 1px solid var(--border); }
.pipeline-step::before { color: var(--muted); font-family: var(--font-mono); font-size: 0.75rem; content: '0' counter(pipeline); }
.pipeline-step p { margin: 0.4rem 0 0; color: var(--muted); }

.filter-bar { display: flex; flex-wrap: wrap; gap: 0.6rem; margin-bottom: var(--gap-xl); }
.filter-button { min-height: 2.75rem; padding: 0.65rem 0.9rem; border: 1px solid var(--border); border-radius: var(--radius); background: transparent; color: var(--muted); cursor: pointer; }
.filter-button:hover, .filter-button[aria-pressed='true'] { border-color: var(--fg); color: var(--fg); }
.archive-count { margin-left: auto; align-self: center; color: var(--muted); }

.publication-card { display: grid; grid-template-columns: minmax(13rem, 0.42fr) minmax(0, 1fr); gap: var(--gap-xl); padding-block: var(--gap-xl); border-top: 1px solid var(--border); }
.publication-card:last-child { border-bottom: 1px solid var(--border); }
.publication-card .media-frame img { aspect-ratio: 4 / 3; }
.publication-copy { align-self: center; }
.publication-copy h2 { font-size: clamp(1.8rem, 3.6vw, 3.4rem); }
.publication-copy p { max-width: 58ch; margin: 1rem 0 0; color: var(--muted); }
.publication-copy .text-link { margin-top: 1.5rem; }

.cta-strip { text-align: center; }
.cta-strip .container { max-width: 52rem; }
.cta-strip .lead { margin: var(--gap-md) auto var(--gap-lg); }
.cta-strip .hero-cta { justify-content: center; }

.pagefoot { padding-block: var(--gap-xl); border-top: 1px solid var(--border); color: var(--muted); }
.footer-grid { display: grid; grid-template-columns: 1fr auto; gap: var(--gap-xl); align-items: end; }
.footer-brand { display: flex; align-items: center; gap: 0.9rem; }
.footer-brand img { width: 2.6rem; height: 2.6rem; border-radius: 50%; }
.footer-links { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: var(--gap-lg); }
.footer-links a:hover { color: var(--fg); }
.footer-note { margin: 1rem 0 0; font-size: 0.85rem; }

[data-reveal] { transition: opacity 500ms ease, transform 650ms cubic-bezier(0.2, 0.7, 0.2, 1); }
[data-reveal].will-reveal { opacity: 0; transform: translateY(1rem); }
[data-reveal].is-visible { opacity: 1; transform: translateY(0); }

@media (max-width: 920px) {
  .grid-2, .grid-3, .grid-2-1, .grid-1-2, .split-panel, .section-heading, .publication-card { grid-template-columns: 1fr; }
  .hero { min-height: auto; }
  .hero-split { grid-template-columns: 1fr; }
  .hero-copy h1 { max-width: 11ch; }
  .section-heading .lead { justify-self: start; }
  .fold-frame { min-height: 27rem; }
  .section-fold::before { left: auto; right: 8%; }
  .publication-card .media-frame { max-width: 34rem; }
}

@media (max-width: 760px) {
  .menu-toggle { display: grid; }
  .nav-menu { position: fixed; top: 4.75rem; right: 0; bottom: 0; left: 0; display: flex; flex-direction: column; align-items: stretch; gap: 0; padding: 1.5rem var(--gutter); background: var(--bg); opacity: 0; visibility: hidden; transform: translateY(-0.75rem); transition: opacity 180ms ease, transform 180ms ease, visibility 180ms ease; }
  .nav-menu.is-open { opacity: 1; visibility: visible; transform: translateY(0); }
  .nav-link { min-height: 3.5rem; display: flex; align-items: center; border-bottom: 1px solid var(--border); font-size: 0.85rem; }
  .nav-link[aria-current='page']::after { display: none; }
  .log-row { grid-template-columns: 1fr; gap: 0.65rem; }
  .log-row .pull { justify-self: start; }
  .fold-frame { min-height: 23rem; }
  .footer-grid { grid-template-columns: 1fr; align-items: start; }
  .footer-links { justify-content: flex-start; gap: 1.25rem; }
  .filter-bar { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .archive-count { grid-column: 1 / -1; margin-left: 0; }
  .hero::after { display: none; }
  .flowmap-frame { min-height: 27rem; box-shadow: 1rem 1rem 0 var(--accent-soft); }
}

@media (max-width: 430px) {
  :root { --gutter: 1.15rem; }
  .brand-name { font-size: 0.98rem; }
  .hero-cta { align-items: stretch; flex-direction: column; }
  .btn { width: 100%; }
  .fold-frame { min-height: 19rem; }
  .fold-caption { right: 7%; bottom: 7%; left: 7%; width: auto; }
  .principle-row, .pipeline-step { grid-template-columns: 2.5rem 1fr; gap: 0.75rem; }
  .filter-bar { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
  [data-reveal].will-reveal { opacity: 1; transform: none; }
}